Clifford D. Simak 
Trouble with Tycho and Cosmic Engineers 

Adventurers journey into the foreboding unknown regions of outer space in these two classic science fiction tales from the Hugo and Nebula Award–winning author.The Trouble with Tycho Prospecting on the moon is grim, dangerous, and usually unrewarding. Most greenhorns don’t know that until after they arrive, and Chris Jackson is no exception. He put everything he owns, and then some, into this venture, and he’ll be ruined if he fails. Jackson’s last chance at success is hidden in the uncharted crater Tycho—where three expeditions have already disappeared. Jackson, a beautiful immigrant, and a visiting doctor set out to find their fortunes . . . and discover whether the terrifying rumors of what lurks within Tycho are true.Cosmic Engineers “Upon you and you alone must rest the fate of the universe. You are the only ones to save it.” Thus spoke the mysterious Cosmic Engineers to a small group of human beings on the rim of the Solar System. Courageously journeying beyond uncharted stars, somewhere in the vastness of the galaxy, they will meet the greatest challenge of their lives—the catastrophic fury of the Hellhounds of Space.